Answer:
Step-by-step explanation:
Givens
C = 12 * pi
C = 2*pi * r
Solution
2*pi * r = 12*pi Divide both sides by 2pi
2*pi * r/ 2*pi = 12*pi/2pi
r = 6
Answer: the diameter = 2 * r
the diameter = 12
the first one
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